A mixture of 1,2-Dihydro-2-oxo-5-pyrimidinecarboxylic acid ethyl ester (3.60 g, 21 mmol), phosphorus oxychloride (25 mL), and N, N-dimethylaniline (2.5 mL) was heated to reflux for 1.5 h. After removal of the solvent, ice water (10 mL) was added to the residue. The mixture was added to 2 N NaOH (90 ml) and extracted with EtOAc. After work, the residue was purified by column chromatography on silica gel (ethyl acetate in petroleum ether, 5 per cent v/v) to give the product Ethyl 2-chloropyrimidine-5-carboxylate (1.20 g, 30 per cent).
